Compiler plugin crashes when using a new-expr with a user-defined class in the same source

[MaryamZi]

Description:
$title. Had to use an object constructor as a workaround, but this is not quite an acceptable solution if one needs to use the class in multiple places.

Steps to reproduce:

import ballerina/websubhub as _;

class Foo {
    
}

public function main() {
    _ = new Foo();
}

error: compilation failed: The compiler extension in package 'ballerina:websubhub:1.2.1' failed to complete. class io.ballerina.compiler.syntax.tree.SimpleNameReferenceNode cannot be cast to class io.ballerina.compiler.syntax.tree.QualifiedNameReferenceNode (io.ballerina.compiler.syntax.tree.SimpleNameReferenceNode and io.ballerina.compiler.syntax.tree.QualifiedNameReferenceNode are in unnamed module of loader 'app')

Affected Versions:
1.2.1